The answer is b because it is equivalent.
Easy
when rock is in water, it takes up a certain volume, say x
so
initial+x=final volume
luckily we have final and inital
13.7ml+x=28.9ml
minus 13.7ml both sides
x=15.2ml
the volme of the rock is 15.2ml
Answer: 2343 / 256
Explanation
I will do this for you in two forms: 1) adding each term, and 2) using the general formula for the sum of geometric series.
1) Adding the terms:
4
∑ 3 (3/4)^i = 3 (3/4)^0 + 3 (3/4)^1 + 3 (3/4)^2 + 3 (3/4)^3 + 3 (3/4)^4
i=0
= 3 + 9/4 + 27/16 + 81/64 + 243/256 = [256*3 + 27*16 + 64*9 + 4*81 + 243] / 256 =
= 2343 / 256
2) Using the formula:
n-1
∑ A (r^i) = A [1 - r^(n) ] / [ 1 - r]
i=0
Here n - 1 = 4 => n = 5
r = 3/4
A = 3
Therefore the sum is 3 [ 1 - (3/4)^5 ] / [ 1 - (3/4) ] =
= 3 [ 1 - (3^5) / (4^5) ] / [ 1/4 ] = 3 { [ (4^5) - (3^5) ] / (4^5) } / {1/4} =
= (3 * 781) / (4^5) / (1/4) = 3 * 781 / (4^4) = 2343 / 256
So, no doubt, the answer is 2343 / 256
Answer:
The graph is positive and decreasing for all real values of x where x < -1
Step-by-step explanation:
we have
The function is a vertical parabola open up
The roots (x-intercepts) are x=3 and x=-1
The vertex is the point (1,-4 ) is a minimum
using a graphing tool
see the attached figure
we know that
In the interval (-∞,-1) ---> the function is positive and decreasing
In the interval (-1,1) ---> the function is negative and decreasing
In the interval (1,3) ---> the function is negative and increasing
In the interval (3,∞) ---> the function is positive and increasing
therefore
The graph is positive and decreasing for all real values of x where x < -1
Answer:
It is C.
Step-by-step explanation:
The centre of the circle is at the midpoint of The diameter = (8+2)/2, (6+0)/2 = (5,3) so the left side of the equation is (x-5)^2+(Y-3)^2. Now we need to work out the radius:
The diameter = square root(8-2)^2+6^2) = square root of 72 = 6sqrt2.
So the radius = 3sqrt2 and r^2=18.
